A microphone has been conventionally used to make measurement in the method of measuring the crispness (so-called crispy texture) of deep-fried food products such as tempura (Japanese fritter-like dish) and korokke (a kind of croquette). However, there are differences in the perception of the crispness among individuals and its evaluation was subjective. What is more, the sensory factor which may cause people to perceive crispness has been less studied.
Under the circumstances, Patent Literature 1 discloses a method of evaluating the texture of a porous food product, the method comprising: subjecting sound and/or vibrations occurring during the breakage and/or mastication of a porous food product such as a deep-fried food product to acoustic analysis using the sharpness and/or roughness as the amount for acoustic evaluation, and using the numerical values obtained by the acoustic analysis to evaluate the crispness of the porous food product without evaluation through the sensory test.
Patent Literature 2 discloses a device for measuring the physical properties of a food product, wherein the texture value of the food product is obtained by inserting a thrust jig having projections and recesses formed on lateral faces thereof, into a sample such as the food product, detecting vibrations occurring during the insertion, performing Fourier transform to convert the vibrations into a vibration spectrum, and carrying out an operation of the vibration spectrum and a coefficient table.